Closed heat treating chamber having a seal roll oscillating mechanism



CLOSED HEAT TREATIb IG CHAMBER HAVING-A SEAL R0 OSCILLATING MECHANISM Filed Feb. 24, 1965 2. Sheets-Sheet l &

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United States Patent Ofiice 3,306,594 Patented Feb. 28, 1967 3,306,594 CLOSED HEAT TREATING CHAMBER HAVING A SEAL ROLL OSCILLATING MECHANISM Fritz E. Bauer, North Adams, Mass., assignor to Crompton & Knowles Corporation, Worcester, Mass., a corporation of Massachusetts Filed Feb. 24, 1965, Ser. No. 434,951 3 Claims. (Cl. 263-3) This application relates to apparatus for the elimination of heat stress distortion in seal rolls used in conjunction with a heated pressure chamber for the continuous processing of web materials.

Certain we-b materials such as cotton fabrics require, during their processing, the application of wet or dry heat sometimes under relatively high pressures. This treatment is applied in pressure vessels having roll sealing devices which prevent the loss of heat and, in some cases, pressure around the web as it enters and leaves the chamber. These rolls consist of a top and bottom roll through which the fabric passes. One side of the pair of rolls is exposed to atmospheric pressure and the other side is exposed to the interior of the pressure chamber. Conventional insulation surrounds the rolls on the sides away from the web. During the initial start-up of the process the rolls are exposed to heat from the chamber and the cold air of the atmosphere. This uneven heating causes distortion of the rolls and consequent damage to both the rolls and their fittings. If the movement of the web were commenced at the same time as heat to the chamher is first started, the web material would pass out of the chmaber in an incompletely finished condition until the operating temperature is reached. In that event, so much web material would be in an incompleted state as to render the process uneconomical.

In order to solve the above problem the apparatus of my invention is provided with means for oscillating the rolls during start-up so that the surface of each roll is alternately exposed to the heat and the cold thereby being evenly heated and, yet, the web material is retained in virtually its original position until fully treated.

My invention wil lbe explained in further detail below and in reference to the accompanying drawings in which:

FIG. 1 is a vertical sectional view of a pressure vessel and a system of rolls for transporting a web therethroug-h, and

FIG. 2 is a schematic view of one form of driving means connected to the roll system for transporting the web and oscillating it in accordance with the invention.

Referring to FIG. 1, the pressure vessel has at one end a pair of entrance seal rolls 11 mounted in a housing 11a. Within .the vessel are guide rolls 12 and powered bottom rolls 13. Rolls 14 are dancer rolls which are free to move vertically and maintain a constant tension in the web W. From entrance rolls 11, the web passes in a series of loops over the guide rolls 12 and under the bottom rolls 13 and dancer rolls 14, thence under a guide roll 12a and finally out through exit seal rolls 15 mounted in housing 15a. The housings 11a and 15a and their respective seal rolls 11 and 15- may be constructed as disclosed in US. Patent No. 3,040,553 granted June 26, 1962.

The web within the vessel chamber 16 is exposed to heat in the conventional manner for fabric processing. Also, the chamber 16 is usually maintained under superatmospheric pressure in the conventional manner, to facilitate procesing of the web material.

In operation, the web 10 passes continuously through the powered seal rolls 11 and 15 and the chamber 16 between them. At start-up, however, the driving means for the seal rolls 11 and 15 and the drive rolls 13 are operated to oscillate them in synchronization.

Alternatively, only rolls 11 and 15 need be powered while rolls 14 take up the slack from the Web. A further alternative powering setup is to rotate rolls 11 and 15 separately without regard to the motion of the other roll. In this last case the movements must be limited in such a manner as to prevent tearing of the web.

The oscillation contemplated consists of at least enough rotational motion to expose the entire surface of rolls 11 and 15 to the heat and atmosphere alternately. In addition, the speed of oscillation is sutficiently great so as to prevent cooling of the atmospherically exposed surfaces. As is apparent, any of the many conventional oscillating apparatuses may be utilized in my invention to produce the desired effect.

Referring to FIG. 2, the upper roll 11 of the entrance pair has a shaft 11b extending through a bearing (not shown) in the adjacent wall in housing lla. Outside the housing, this shaft carries a sprocket 20 and also a gear 21, the latter meshing with a similar gear on a corresponding shaft of the underlying roll 11 (not shown). Likewise, the upper roll 15-of the exit pair has a shaft 15b extending through a bearing in the adjacent wall of housing 15a; and outside the housing this shaft carries a sprocket 22 and a gear 23. The latter meshes with a similar gear on a corresponding shaft to the underlying exit roll (not shown). Thus, the rolls of each pair 11 and 15 are driven in opposite directions through the respective gearing 21 and 23.

The sprockets 20 and 22 are connected through chains 24 and 25 to spockets 26 and 27, respectively, mounted on a drive shaft 28. The latter constitutes the output shaft of a conventional transmission 29 providing a reversible output. Shaft 28 is driven through the transmission 29 from an electric motor 30' or other power source.

The direction of rotation of shaft 28 is determined by a reversing element 31 in the form of a lever pivoted at 32 and connected at its inner end to the clutch (not shown) of the transmission 29. Normally, the lever 31 is held by a tension spring 33 in the position shown in FIG. 2; and in this position the transmission clutch is positioned to drive the seal rolls 11 and 15 in the direction to draw the web W through chamber 16 from the entrance seal rolls 11 to the exit seal rolls 15. When lever 3-1 is swung to a second position against the action of spring 33, the transmission clutch is positioned to reverse the rotation of shaft 28 and the seal rolls 11 and 15 and thus move the web in the opposite direction.

Movement of lever 31 against the action of spring 33 is effected by a solenoid 34, the plunger of which is connected to the outer end of the lever. The coil of solenoid 34 is included in a circuit comprising a manual switch 35, a current source 36 and an automatically operated switch 37. Switch 37 is operated by a cam 38 on shaft 28 and is of the type which closes when actuated a certain number of times by cam 38 (through rotation of shaft 28 in one direction) and then opens when again actuated a certain number of times by cam 3-8 (through rotation of shaft 28 in the opposite direction). The parts 34 through 38 constitute in effect a start-up means as Will be described presently.

As shown, the drive shaft 28 also carries a sprocket 40 which drives the bottom rolls 13 through chain 41 and sprockets 42.

In preparing for a web-treating operation, the leading end of web W is passed between or around the various rolls in the manner shown in FIG. 1, and the chamber 16 is heated up in the usual manner. During the heat-up period, which maybe approximately 30 minutes, the motor 30 is operated while the manual switch 35 is closed. Consequently, when shaft 28 is rotated a certain number of times, switch 37 closes so as to energize solenoid 34- and swing the lever 31 to its position for reversing the rotation of shaft 218. When this shaft has undergone a certain number of revolutions in the reverse direction, switch 37 is reopened so as to de-energize solenoid 34, whereby spring 33 returns lever 31 to its normal position in which rotation of shaft 28 is again reversed. This action is repeated automatically throughout the heat-up period, causing the seal rolls and web to oscillate back and forth. As a result, the seal rolls 11 and 15 are heated uniformly to the operating temperature due to the fact that each portion of their surfaces is subjected alternately and briefly to heat from chamber 16' and atmosphere from the open outer ends of housings 11a and 15a. Preferably, the switch 37 is set to provide one full revolution of the seal rolls in each direction, which corresponds to a plurality of revolutions of drive shaft 28 in each direction.

When the necessary heat-up time has elapsed, the

manual switch 35 is opened to render the start-up means 34-38 inoperative. Spring 33 will then retain the revers ing lever 31 in its normal position for moving the web continuously through chamber 16 from the entrance rolls 13 to the exit rolls 15. It will be apparent from the foregoing that the oscillations provided by the start-up means 3438 serve to avoid distortion of the seal rolls under the action of heat from chamber 16, without any substantial waste of web material; and once the chamber 16 has been heated to operating temperature, the reversing element 31 is retained in its position for normal operation of the roll system.

I claim:

1. In an apparatus for the continuous application of heat to a web, said apparatus comprising a closed vessel forming a heat-treating chamber and having entrance and exit openings for the web, a pair of seal rolls at the entrance opening adapted to engage opposite sides of the web, a second pair of seal rolls at the exit opening adapted to engage opposite sides of the web, and internal rolls mounted in the chamber for passing the web in loops through the chamber from one pair of seal rolls to the other pair, the improvement which comprises reversible driving means connected to said seal rolls for rotating them and including a reversing element operable in a first position to drive the seal rolls in the direction to draw the web from said entrance to said exit opening, said element being operable in a second position to drive the seal rolls in the opposite direction, start-up means operatively connected to said element for moving it alternately from one of said positions to the other to oscillate the seal rolls and web, and means for rendering said startup (means inoperative.

2. Apparatus according to claim 1, comprising also a driving connection between said driving means and at least one of said internal rolls.

3. Apparatus according to claim 1, in which said driving means includes a shaft and a cam on the shaft, said start-up means including a member operable by said cam.

References Cited by the Examiner UNITED STATES PATENTS 1,869,900 8/ 1932 La-udenberger 266-3 X 2,351,987 6/1944- Lynn 2663 3,040,553 6/1962 Rust 34-242 X FREDERICK L. MATTESON, JR., Primary Examiner.

J. J. CAMBY, Assistant Examiner, 

1. IN AN APPARATUS FOR THE CONTINUOUS APPLICATION OF HEAT TO A WEB, SAID APPARATUS COMPRISING A CLOSED VESSEL FORMING A HEAT-TREATING CHAMBER AND HAVING ENTRANCE AND EXIT OPENINGS FOR THE WEB, A PAIR OF SEAL ROLLS AT THE ENTRANCE OPENING ADAPTED TO ENGAGE OPPOSITE SIDES OF THE WEB, A SECOND PAIR OF SEAL ROLLS AT THE EXIT OPENING ADAPTED TO ENGAGE OPPOSITE SIDES OF THE WEB, AND INTERNAL ROLLS MOUNTED IN THE CHAMBER FOR PASSING THE WEB IN LOOPS THROUGH THE CHAMBER FROM ONE PAIR OF SEAL ROLLS TO THE OTHER PAIR, THE IMPROVEMENT WHICH COMPRISES REVERSIBLE DRIVING MEANS CONNECTED TO SAID SEAL ROLLS FOR ROTATING THEM AND INCLUDING A REVERSING ELEMENT OPERABLE IN A FIRST POSITION TO DRIVE THE SEAL ROLLS IN THE DIRECTION TO DRAW THE WEB FROM SAID ENTRANCE TO SAID EXIT OPENING, SAID ELEMENT BEING OPERABLE IN A SECOND POSITION TO DRIVE THE SEAL ROLLS IN THE OPPOSITE DIRECTION, START-UP MEANS OPERATIVELY CONNECTED TO SAID ELEMENT FOR MOVING IT ALTERNATELY FROM ONE OF SAID POSITIONS TO THE OTHER TO OSCILLATE THE SEAL ROLLS AND WEB, AND MEANS FOR RENDERING SAID STARTUP MEANS INOPERATIVE. 